Locking structure for securing a fluid transfer tube

Abstract

A test sample card is provided with a locking feature for achieving a positive, locking engagement with a transfer tube that conducts fluid into the interior of the test sample card. The locking feature consists of a tubular channel inwardly disposed from the fluid intake port that has an inner annular rim defining a restriction. The annular rim is of a reduced diameter relative to the diameter of the transfer tube. A recessed region is positioned inwardly from the restriction that has an opening in one of the surfaces of the card body. When the transfer tube is inserted into the tubular channel, the first end is forced past the restriction into the recessed region, with the annular rim compressing the transfer tube. The user is able to sense with their hands when the first end is inserted past the restriction. Visual observation of the first end of the transfer tube through the opening in the card surface confirms that the transfer tube has been properly inserted into the test sample card.

We claim:  
     
       1. A method for securing a resilient, tubular-shaped fluid transfer tube to a fluid intake port, comprising the steps of: 
       inserting a first end of said transfer tube into said fluid intake port;  
       said port comprising a restriction within said fluid intake port, said restriction comprising an annular region formed of a substantially rigid material of reduced diameter relative to the diameter of said first end of said transfer tube;  
       pushing said transfer tube further into said fluid intake port until said first end of said transfer tube makes contact with said restriction;  
       urging said first end of said transfer tube past said restriction into a recessed region in axial alignment with said fluid intake port and said restriction, said recessed region further comprising a stop inward of said restriction, said urging causing said resilient transfer tube to compress as it passes said restriction and to terminate at said stop, said recessed region having a diameter greater than or equal to the diameter of said first end of said transfer tube and allowing said first end of said transfer tube to expand to substantially its original diameter to thereby sealingly lock said transfer tube to said fluid intake port,  
       observing through a window or optically clear region in said fluid intake port whether said first end of said transfer tube has been inserted into said recessed region, the presence of said transfer tube in said recessed region indicating that said transfer tube has been inserted properly in said fluid intake port to said stop; and  
       thereafter admitting a fluid through said transfer tube into said fluid intake port with said transfer tube properly inserted into said fluid intake port whereby leakage of air into said fluid intake port may be avoided.  
     
     
       2. The method of claim  1 , wherein said fluid intake port is formed in a test sample card, said test sample card further comprising an intake manifold in axial alignment with said restriction, and the method further comprising the step of stopping the insertion of said transfer tube at a predetermined location with said stop so that said transfer tube does not enter said intake manifold. 
     
     
       3. Fluid supply and connection apparatus, said apparatus formed of an opaque material, comprising in combination: 
       a resilient fluid intake transfer tube and having a first end and a second end for placement in fluid communication with a fluid;  
       a fluid intake port in said apparatus for receiving said fluid, said fluid intake port comprising an intake port and a tubular channel in coaxial alignment with said intake port for receiving said transfer tube, said channel having an annular compression locking means formed of a substantially rigid material disposed within said channel for compressibly securing said transfer tube within said fluid intake port after said first end of said transfer tube has been inserted into said channel past said annular compression locking means;  
       a recessed region in alignment with said locking means receiving said first end of said transfer tube after said first end of said transfer tube has been inserted past said locking means, said recessed region further comprising a stop inward from said restriction, said recessed region sized to allow said first end of said transfer tube to expand to substantially its original diameter after being inserted past said locking means; and  
       a window or optically clear region in said apparatus surrounded by said opapque material for permitting visual inspection of said first end of said transfer tube after said transfer tube has been inserted into said channel past said pular compression locking means to said stop;  
       whereby a fluid is admitted through said transfer tube into said fluid intake port after said first end of said transfer tube has been inserted past said annular compression locking means to said stop and leakage of air into said fluid intake port may be avoided.  
     
     
       4. The apparatus of claim  3 , wherein said window or optically clear region comprises an opening in said opaque material covered by a transparent membrane. 
     
     
       5. The apparatus of claim  3 , wherein said window or optically clear region comprises an optically clear region provided in said apparatus, said optically clear region surrounded by said opaque material. 
     
     
       6. The apparatus of claim  3 , wherein said transfer tube comprises a resilient plastic material. 
     
     
       7. The apparatus of claim  3 , wherein said fluid supply and connection apparatus comprises a testing device for testing a fluid sample.